Production of dyeings and prints on mixed fabrics



' Patented Nov. 8,1'932 ,UNITED STATES rA'rlazur ,OFFIcEQ HEINRICHWERDENBEBG, or NEU-ALLscHwIL NEAR AsnL, SWITZERLAND, ASSIGNOB TO THEFIRM OF'DURAND & HUGUENIN s. A., or BASEL, SWITZERLAND PRODUCTION OFDYEIINGS AND PRINTS ON MIXED FABRICS i "No Drawing. Application filedMarch 12, 1931, Serial No. 522,155, mi in Germany March 17,1930.

In U. S. patent application Ser, No. 480,- 027, filed Septemberfi, 1930,a processvfor dyeing cellulose ester fibre with gallocyanine,dyestuifshas been disclosed. This process 3.. is based on theobservation that thesegal- =locyanine dyestuffs have in their leucoforma better aflinity for the said fibre than in the oxidized form.Therefore it is advantageous to bring a leuco compound of a gallocyaninedyestufi' onto the cellulose ester fibre and to develop thedyeingthereon by means of a suitableoxidizing agent. 7

The application of the above mentioned M dyestuff-class on cotton fibreproceeds in a v somewhat different manner as the gallocyanines in theform of the dyestuffs themselves I as Well as in the form of their leucocompounds show an insufiicient aflinity for the 11"bre. To realize thefixation thereon, a gal- I locyanine or'its leuco compound is thereforeprinted or padded on the fibre together with a chromium salt, whereupontheidesired dyeing is developed as an insoluble chromium I lake by meansof steaming.

By these means, however, it is not yet p'ossible to dye or printmixturesof cellulose ester and cottonv in a satisfactory manner. The firstmentioned dyeing process is suitable for dyeing the cellulose esterfibre, but the cotton contained in the fabric mixture is dyedquiteinsufiiciently. On the other hand the 5 process with chromiumsalts, such as it is applied to'cotton, is quite unsuitable forcellulose esters, as the latter fibre possesses only a very slightabsorbing property for the chromium lake which is formed.

1 Mixed fabrics, however, containing 40 lulose ester fibre and a cottonfibre, i. e. vegetable cotton or artificial silk being based on acellulose material such asviscose, coppersilk (Bemberg silk)eetc.,are-used actually to a large extent and the dyeing or printing of suchfabrics has become an important problem. i It has now been found that itis possible to dye such mixed fabrics evenly with galloeyw aninedyestuffs if one works first in an ancelalogous manner to that describedin the aforesaid U. S. patent application for pure cellulose'esterfibre, that is to say if a gallocyanine dyestufi is brought onto thefabric in the form of its leuco compound, if this fibreis.

steamed, whereby the fixationof the dyestuif idized to the dyestufl'.This oxidation and,-

simultaneously the-fixation of the dyestuif on the cotton fibremay beperformed by an after-treatment of the fabric in an acid biehromatesolution.

in the same Way as in the process of the aforesaid U. S. patentapplication, also in the present one, simultaneously with the dyestuif asuitable oxidizing agent, inactive in the cold, active in hot state andincapable of causing the formation of a lake with the dyestuif, may bebrought onto the fabric. After steaming the dyestutf is fixed anddeveloped on the cellulose ester fibre and by'an after-treatment with asuitable chromium compound the fixation of the dyestuif on the cottonfibre can be performed.

The improved process is illustratedby the following examples. i

The following printing pastes are prepared:

Heat up to dissolve,cool down and add:

I Turpentine oil 20 Sodium chlorate solution (1:3) 80 E wample II PartsLeuco Correine R R (see Colour Index No. 900) Hot water 120 Gumthickening 350 Neutral starch and gum dragon thickening 400 Heat up todissolve,cool downand add Turpentine oil Sodium chlorate solution (1:3)80 1000 Emample [II Parts I diethylparaphenylenediamine s e e ColourIndex No. 884) Hot water 120 'Gum thickening 350 Neutral starch and gumdragon thickening 400 Turpentine oil 20 Sodium chlorate solution (1: 3)80 Print these pastes on mixed fabric of acetate silk and cotton, dry,steam for 1 hour,

. treat afterwards at ordinary temperature in a bath containing 5 gr. ofbichi'omate of soda per liter of water, and wash. Thus one obtainsevenly developed and normal dyeings on both kinds of fibres.

In these cases instead of bichromate'in an analo ous manner anotherchromium com pound such as for instance chromium acetate may be usedwith a similar result.

Example V Parts Prune (see Colour Index No. 893 30 Hot water 342'Hydrosulphite NF conc. (powder) 8 -Heat up until completely reduced,

then add: Neutral starch and gum dragon thickening; 600 Cool down andadd: Turpentine oil 20 'Print on mixed fabric, steam for 40 minutes.After steaming treat in a bath containing 10 gr. of sodium bichromateand 10 com.- of formic acid (85 per cent) per liter for 10 to 15minutes, rinse and soap.

When using a printing paste which contains a chromium salt, such as forinstance chromium acetate, only uneven and dull shades are obtained, asin this (latter) case the acetate silk fibre is dyed only very slightly.

By the present process, dyeings on mixed fabrics may also be produced bypadding.

In this process the gallocyanine dyestuffs may also be used inmixtureswith dyestuffs of other classes capable of being absorbed by thecellulose fibre and of being fixed on cotton fibre as a chromium lakesuch as for instance yellow wood extract.

What I claim is 1. A. process for producing dyeings and prints on mixedfabrics containing cellulose ester fibre and a cotton fibre by means ofgallocyanine dyestufis, which consists in bringing a gallocyaninedyestuif in form of its leuco compound onto the fabric, subjecting thesame to a steaming operation, necessary for the fixation of the dyestuffon the cellulose ester fibre, and then after-treating the fabric with asuitable chromium compound to produce fixation of the dyestuff on thecotton 2. A process for producing dyeings and prints on mixed fabricscontaining cellulose I ester fibre and a cotton fibre by means of'of'the dyestufi on the cotton fibre.

3. A process for producing :dyeings and prints on mixed fabricscontaining cellulose ester fibre and a cotton fibre by means ofgallocyanine dyestufis, which consists in bringing onto the fabric agallocyanine dyestuff in form of its leuco compound simultaneously withan oxidizing agent, which is inactive in the cold, but becomes active toperform the necessary oxidizing action in hot state, subjecting thefabric to a steaming operation for thefixation of the dyestuff on thecellulose ester fibre and then after-treating same with a suitablechromium compound to produce the fixation of the dyestuif on the cottonfibre.

In witness whereof I have hereunto signed myname this 2nd day of March1931.

HEINRICH WERDENBERG.

